Need help with all the settings on my Classic 150

[bee88man]

Really need to know your lowest seasonal outdoor temp...it is used for the 'string' calculator. Lowest temps are times of highest voltage from PV panels. Too high of voltage can damagea Classic or any other CC.

[ClassicCrazy]

Larry, I do have a new modem that I think can also serve as a wireless network bridge. It has several Cat5 sockets in the back. This will require a long cable because the modem is two rooms over from where the Classic is.
So my partner said he'll be willing to run the wire under the house and we'll probably do that. Will one of these APPs provide the means for me to get ALL the Classic's info onto my Mac?  (Or if not my Mac, my partner's PC?)

EDIT:  I finally found the Battery Temp readout in the Classic's display menu. I just wasn't scrolling down the line far enough to find it. Wow I'm dumb! but this is a bit confusing. Temp was 20.6, btw.

Thanks again for the help,
Lisa

Not sure about Macs - I only know about monitoring on  Windows and Android . Maybe on Macs but that is your own geek research to figure out .  An inexpensive Android tablet or find an Android phone someone is not using or getting rid of - there are millions out there.  You can hook up to wifi with an android without have to pay for any phone service and use it's apps.

Larry

[Lisa234]

Bee88man, our lowest seasonal outdoor temp is 40 F. 

Thanks for your help.

Lisa

[Lisa234]

p.s.  I'll attach the PV specs again:

[Vic]

Hi Lisa,

Two things;
  1.  here is the Temp Compensation value for charging your AGM batteries  .
"The effect of temperature on cycle charge voltage: -4 mV / °C / Cell'.
So a change of -5 mV,  to -4 mV is all that is needed.

  2.  Ran the Classic String Sizer,   and the results are attached (used the default high temperature).

You are fine on the effect of cold temps on the Voc.

And,  Beeman,   these Renogy PVs are 60 Cell modules.   It is almost impossible to fine any location on Earth that is too cold for strings of three PVs,  with a Classic 150.

The String Sizer states that Lisa's Classic 150 would enter Hyper Voc at about -95 degrees F,   FWIW.

Vic

[Lisa234]

Vic,  thank you VERY much for running the string sizer for me and getting the info on the T-comp.  I will adjust the setting accordingly. Glad to know my PVs are no threat to my Classic as long as another ice age doesn't befall us.

So anyway -- awesome! I feel like I have this thing fairly well figured out now which is pretty cool because four days ago I was like - I'm never gonna get this!

[Lisa234]

I have a couple more questions.  I noticed yesterday in the manual it says the Absorb time should be "proportional" to the Bulk time -- though it does not say what exactly that 'proportion' should be. So I don't really want to be taking a wild guess on this.  I'm also assuming the Bulk time varies depending on how much the batts are discharged - and so I don't know how to figure out the best setting for the Absorb time.
Also wondering if Absorb time should be manually re-adjusted depending on what's happening with the Bulk time from one day to the next.

(I'm assuming the Ending Amp function won't work for me since I don't have the Whizbang)

[ClassicCrazy]

Yeah I don't know what that statement about proportional would mean either. Never timed the Bulk here.
Just leave your 1 to 2 hours absorb time - whatever you decided on using.

It is true that sometimes you won't need the full Absorb time or might need a bit more. That is why ending amps is better since it ends absorb depending on when the amps into the batteries start to level off and you have figured out by testing specific gravity ( if you have flooded lead acid ) or just observed the leveling off point  . Then the Classic would terminate Absorb and go into Float .  So lets say you have 2 hours absorb time but the ending amps setting comes along at 1.5 hours - then it is done with absorb .

But you can't really use ending amps without the Whizbang because you have to know exactly how many amps is going into the battery as opposed to how many amps the Classic is producing - some of which are going into battery and some are going into loads.  You can set that up once on Classic to use the Whizbang amps and then it does it automatically.

I think you said you have a different monitor . If that shows just amps going into the battery you could observe it and figure out the ending amps setting . To do that you would set the ending amps a bit longer , then watch when it goes from Bulk to Absorb. The  Classic at that point will hold the voltage steady at the Absorb setpoint ( or a bit higher or lower depending on the temp compensation if the batteries are hotter or colder) . So you would see it stay at Absorb voltage and the amps going into the battery will start to drop as it charges and the SOC goes up .  There will be a point where the amps starts to taper off and hold steady for awhile without changing much. That would be the ending amps. When you get your Classic plugged into internet  you can set it up on MyMidnite and see the history graphs and see the curve much easier there.

So if you did everything correctly you would see Classic get to ending amps point around the time SOC gets to 100% full.  You other external meter might not be as good an SOC as the Classic and Whizbang unless it take battery temperature and also has an efficiency setting.

So with your other monitoring meter  you might be able to use it to spot the ending amps point and then manually end Absorb on the Classic if you were around watching it. At least you could see close you have your Absorb time set and tweak that better to be more in line with regular usage there.

Hope that all made sense.

Go to the Midnite Knowledge base on their website because they have a lot more details on some of these things that are not in the manual.

Larry

[Vic]

Hi Lisa,

The ideal Absorb time,   will depend on the Depth Of Discharge (DOD)  of the previous battery discharge.   This is one of the reasons that many of us use End Amps to end Absorb.

In early Classic Firmware,   there was an option to have the Absorb time equal the Bulk time.   Make certain that you have the latest copy of the Manual:
http://www.midnitesolar.com/pdfs/Classic_ClassicSL_Manual_10-001-1_REV_L.pdf

AND,   what is the Classic Firmware that is in your Classic?

AGM batteries need a fairly long Absorb time,   (especially with parallel battery strings),   on occasion.   This long time can help keep the battery strings well-balanced.

The inexpensive WbJr,   and a Shunt would probably be a useful addition to your system (as noted previously):
https://www.solar-electric.com/midnite-solar-whiz-bang-jr-current-sense-module.html

Shunt:
https://www.solar-electric.com/mkb-500-50.html

There may be a  proper Shunt in your system,   if the system has an e-panel,  or MNDC.

Sometimes,  using the Mid Nite Shunt can be useful,    as it has provisions for a busbar to be attached to one side of the shunt:
https://www.solar-electric.com/midnite-solar-shunt.html

AGM batteries are a good solution for many systems,   but,  it is more difficult to determine the proper Absorb time,   about the only method of determining actual SOC,    is from the resting voltage,   or from Ending Amps.   On the systems here,  using Flooded Lead Acid (FLA) batteries,   the proper EA varies (at least somewhat),   depending on the DOD of the battery.

There is a trick,   that can be used on 12 or 24 V systems with two battery strings.  This is to use a battery switch (a string 1, 2, or Both switch).   This can allow  one to separate the two battery strings,   over night. The disconnected string Rests overnight.   The Resting battery voltage of that string is measured in the morning.  This voltage (when temp compensated),  is a very good indication of the actual SOC of that string.   The following day,   the other string can be similarly Rested to check its SOC.

A possible switch:
https://www.solar-electric.com/basw1300amp.html

More later,   FWIW,   Vic

[Lisa234]

I think getting the Whizbang might be the easier way to go than getting a switch. But this will require my partner to go back to work re-arranging our set up. Wish the WBjr had come with the kit.

Anyway, I do have one other idea or something that will get us by for awhile. What if I turn all the loads off when its bulking and put the End Amps on 6amps (correct setting for my 400 AH system, yes?)  I could be sure to get a nice full charge and, also, see how long it takes for Absorb to switch to float absent a load.   I could note that time and then maybe do some math, figuring in the difference there might be with the loads on.  I'll be putting the same loads on it every day, which is 450 watts.

I didn't update my manual with any new firmware. I'll get on that when I have a chance.

Anyway, thanks Bob and Larry really appreciate your help. Tell me what you think of my idea for using the Ending Amp function...

Lisa

[Lisa234]

Hey guys, attached is a picture of our shunt that goes with our Renogy battery monitor.  Would that work with the WBjr?

Specs:

Universal Battery Monitor- Voltage range 10V-120V and up to 500A
Accurate Battery SOC%

[Lisa234]

And here is a sample picture of our batt monitor.  (This is NOT actually our monitor, just the pic of it from the internet.)  I don't think it's able to tell me what amps are going into the battery...unless I'm missing it ?

(Also, I don't know what that number 8:44 represents.  Maybe someone could clue me in ? 

Lisa

[Lisa234]

Vic, yes, I must have the old manual because the wording regarding Absorb has indeed changed. They took the part out about "proportional".  Thank you for sending me that link.
Anyway, I just got some good news from Renogy. They told me that I do not have to break in my batteries and its a simple matter of the less used the longer they'll last - period. Well that should make things easy for me! Absorb time can be very short when my batteries are barely discharged. Maybe they'll last my whole life!

[Vic]

I think getting the Whizbang sounds like a better idea than getting a switch. But this will require my partner to go back to work re-arranging our set up because as it's arranged there's no room for the WB. Wish the WBjr had come with the kit.

Anyway, I do have one other idea or something that will get us by for awhile. What if I turn all the loads off when its bulking and put the End Amps on 6amps (correct setting for my 400 AH system, yes?)  I could be sure to get a nice full charge and, also, see how long it takes for Absorb to switch to float absent a load.   I could note that time and then maybe do some math, figuring in the difference there might be with the loads on.  I'll be putting the same loads on it every day, which is 400 watts.

I didn't update my manual with any new firmware. I'll look up what version I have as soon as I have a chance. We got this "kit" about 7 months ago.

Anyway, thanks Bob and Larry really appreciate your help. Tell me what you think of my idea for using the Ending Amp function...

Lisa

Hi Lisa,

Before the introduction of the WbJr,  for the Classics,   and  also,   when using the Outback Power MX-60 CC,  we used CC (total) output current (I call this:  CC EA)  and EA settings to end Absorb.

This works a bit better when the system uses Flooded batteries,  where the actual SG readings can be taken by sampling the actual electrolyte in each cell.   WIth sealed batteries,  like AGMs,  this is not possible.

For systems with fairly repeatable loads on the inverter,   CC EA,  as you described,  should work fine.  Particularly,  when one realizes that,   the loads on the inverter only really matter around the time that the Absorb should be ending.   Even with cyclic loads,   cycling on/off near Absorb end,   CC EA can still work well.   There is just the open question of how one determines weather a particular EA is really allowing the batteries to be fully recharged.

That Renogy Shunt may not be a 50 mV 500 A type.   There is probably a Scale Factor setting that could possibly be made in the Classic,   but   I do not know how to set it,  if it exists.

If you have the manual for the Renogy batt monitor,   each reading of the display should be defined.

Later,  it looks like you have a good handle on your system,   and you have done quite well in getting it installed well,   and are a quick study on the settings for the Classic.  Good Work !!   Vic

[Lisa234]

Thanks Vic, nice of you to say that.  So I just did the Absorb cycle with all my loads removed and Ending Amps set on 7.  I think that was a good idea. Absorb took 50 minutes and I have a feeling it's well charged -- the amps were coming down very slowly right at the end.

So I'm thinking, I'll probably just keep the Ending Amp ON and switch my inverter & load on after it gets into Float.
This would be a really easy routine for me.  We'll probably get the WBjr at some future time, though.